The object of the invention is a device for the improving of the starting of an engine especially during the cold seasons.
The successful starting of an automobile or another such vehicle or heavy duty machine is difficult, during the cold season, particularly after several hours of parking. Especially the starting of an automobile which has been parked outside, over night, in low sub-zero temperatures, is not often successful, because the resistance to revolution in the engine is great due to the stiffness of the lubricating oil, and the reduced battery charge due to the cold. Thus the current available for the starting motor is lowered. Therefore, the chances of the starting of diesel-, petrol- or other corresponding engines is reduced. In addition, cold starting wears the engine and shortens its life.
The German Application Publication DE-OS No. 1 805 862 introduces a thermal battery system, in which there is a heat insulated container arranged in combination with either the oil lubrication or the cooling water system of the engine. Hot lubricating oil, or respectively, cooling water, is stored in the container during the parking-time, and during the starting, it is appropriately transferred with a pump to the corresponding areas of the engine. The container may also be filled with some appropriate heat retaining material, through which the lubricating oil or, respectively, the cooling water, is circulated. In such a case, the oil/water is pumped through the thermal battery when starting the engine, and thus is heated up.
One disadvantage in the thermal battery system described above is that it requires a separate, insulated oil/water container, relatively large in volume, which has to be fitted into the cooling or lubricating oil system of the engine. Such a container must be mounted as close to the engine as possible in order to reduce the loss of heat, and that is cumbersome in old engines due to the lack of space. In addition, the thermal battery system requires additional parts such as for example an additional pump, valves and connecting wires, which increase the expenses.
The German Patent Publication DE-PS No. 1 158 756 introduces a lube economizer which is arranged to operate in combination with the oil pan of an internal combustion engine. There is a conductor coil fitted above the surface of the oil in the oil pan, piercing the wall of it, through which coil a heat-providing fluid is lead. The conductor coil is connected, with a copper cylinder or another heat-conducting organ, to the actual layer of oil on the bottom of the oil pan and to for example a strainer, pump or wires heated therein.
One disadvantage in the lube economizer described above is that the device requires a space in the oil pan and that it can only be installed in new engines. The punctures for the conductor coil in the walls of the oil pan result in sealing problems. In addition, the heat-providing fluid must be acquired from an external source before the starting of the engine. It must be noticed that insulating materials are missing, in which case the heat leakage between the device and the oil pan is of considerable magnitude, and that the ultimate object of the preheating is the total amount of oil in the oil pan.
The German Application Publication DE-OS No. 2 115 221 a device for the improving of the cold starting of an internal combustion engine, in which an electrical resistor is mounted either inside or outside of the oil pan, with which resistor the heating of the engine's lubricating oil in the oil pan is done. The greatest disadvantage in this device is that it requires great amounts of energy especially in low sub-zero temperatures, because the total amount of lubricating oil is intended to be heated or to be kept heated. Thus the electrical resistor has to be connected to a normal electrial network.
The German Application Publication DE-OS No. 2 713 153 has earlier introduced a lube economizer for an internal combustion engine, in which the electrical resistor element is in a strainer situated in the oil pan, through which strainer the lubricating oil is sucked by a pump through the actual oil filter into the engine. Of the disadvantages it can be mentioned that the surface temperature of a single resistor, immersed in the lubricating oil in the oil pan, cannot be raised very high due to the inflammability of the oil. Thus, the effective preheating of the lubricating oil with this device is not possible. In addition, the lubricating oil circulates through the oil pump and filter during the starting and gives up heat into these devices, cooling it before reaching the oil ducts of the engine.